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- G. W. RAYMOND.

Telephone.

No. 242,156. Patented May 31,1881.

UNITED STATES PATENT OFFICE.

CHARLES W. RAYMOND, OF NEW YORK, N. Y.

TELEP-HON E.

SPECIFICATION forming part of Letters Patent No. 242,156, dated May 31,1881.

Application filed January 29, 1881.

To all whom it may concern:

Be it known that 1, CHARLES WARD RAY- MOND, of the city, county, andState of New York, have invented certain Improvements in Telephones, ofwhich the following is a specification.

The invention relates to telephonic transmitters or receivers, electricor mechanical. Heretofore in using an ordinary transmitter or telephonethe speaker placed the mouth close to the mouth-piece of the instrument.Thisis objectionable because, first, the moisture due to condensation ofthe breath collects in the instrument, causingit to rust, therebyimpairing its efficiency second, because the odors of the breath areretained in theinstrument and are often extremely offensive to anotherparty using the same; and, third, when articulation is interfered withthe instrument fails in its purpose in a corresponding degree.

The object of my invention is to avoid the above-mentioned objections,to increase the durability, utility, and efficiency of the instrument towhich it is applied.

The invention consists in a cap covering the mouth ofthe instrument,forming an independent diaphragm not in contact with the diaphragmproper of the instrument, attached in any convenient man ner to thetelephonic transmitter or receiver, and in such a manner as not tointerfere perceptibly with the transmission of sound. This cap orcovering may be made of any suitable material-metal, paper, wood, orrubber, all having been tried and found to work more or lesssuccessfully; but this specification relates more especially to the useof rubber, and rubber and paper combined, that form a cap or coveringapplied to and over themouth-piece of a telephonic transmitter orreceiver. A cap of vulcanized sheet-rubber is molded of such size andshape that it may be placed and stretched over the mouth-piece of theinstrument and retain its position either by its own elasticity or byother means.

In the drawings, Figure 1 is a plan view; and Fig. 2, a section througha: y, showing the cap over a mouth-piece.

The central portion,A, of the cap, when applied, is stretched andbecomes an elastic diaphragm of such a thickness as to not prevent thevibrations of the voice being transmitted by it to the diaphragm proper,t, of the instrument. That portion B B outside the central (No model.)

portion, A, may be made of one or more thicknesses of the same or othermaterial, to better withstand the wear on the corners or edges, and alsoto act as a binding or elastic band to keep the cap in place and thecentral portion drawn sufficiently tight. To counteracta slight musicaltone which this rubber diaphragm may produce there may be insertedinside and under the cap a disk of paper, h, not too thick, and of adiameter a little less than the diameter of the exterior of themouth-piece, between which and the diaphragm Ait is held, as shown. Thevibrations ot' the voice are transmitted from the rubber diaphragm tothe confined air behind it, and thence to the diaphragm proper, t, ofthe instrument, and vice versa when the device is used as areceiving-instrument. The rubber covers the mouth-piece entirely, and isof such a nature that the breath does not condense as rapidly upon it asupon the metallic diaphragm proper of the instrument, and being moreexposed such moisture as is deposited may be easily wiped oh, and in anycase rapidly evaporates, instead of remaining, as usual, within thecavity of the instrument.

The device does not impair the effect of the voice in the instrument toany appreciable degree, but even admits of a more delicate ailjustmentof the instrument itself, thereby increasing the volume of sound, and bypreventing the lips from approaching any closer to the instrument thanthe face of the cap the voice is rendered less disagreeable, the effectmellowed, and articulation madefreea-nd distinct.

What I claim, and d sire to secure by Letters Patent, is-- l. Atelephone in which a supplemental diaphragm covers the mouthpiece,substantially as set forth r 2. Thecombination, in a telephone, of theusual diaphragm at the bottom of the mouthpiece, a diaphragm coveringand extending over the mouth-piece, and a. disk, h, beneath the outerdiaphragm, substantially as described.

In testimony whereof have signed my name to this specification in thepresence of two subscribing witnesses.

OHARLES WARD RAYMOND.

Witnesses H. M. ONEIL, W. A. WILMOT.

